# What You Need:
→ Vanilla Cake
01 - 3 cups all-purpose flour
02 - 2 1/2 teaspoons baking powder
03 - 1/2 teaspoon salt
04 - 1 cup unsalted butter, room temperature
05 - 2 cups granulated sugar
06 - 4 large eggs, room temperature
07 - 1 tablespoon vanilla extract
08 - 1 1/4 cups whole milk
→ Buttercream
09 - 2 cups unsalted butter, room temperature
10 - 6 cups powdered sugar, sifted
11 - 2 teaspoons vanilla extract
12 - 3–4 tablespoons heavy cream or milk
13 - Teal gel food coloring
→ Geode Decoration
14 - 2 cups rock sugar crystals (clear or white)
15 - Teal gel food coloring
16 - Edible gold leaf or gold luster dust
17 - Clear alcohol (such as vodka), for painting
→ Assembly
18 - Simple syrup (optional, for moistening cake layers)
# Step-by-Step:
01 - Preheat oven to 350°F. Grease and line three 8-inch round cake pans with parchment paper.
02 - In a medium bowl, whisk together the all-purpose flour, baking powder, and salt until evenly combined.
03 - Using an electric mixer, beat unsalted butter and granulated sugar together until light and fluffy.
04 - Add eggs one at a time, mixing well after each addition, then blend in vanilla extract.
05 - Alternate adding the dry ingredient mixture and whole milk to the butter mixture, starting and ending with dry ingredients.
06 - Divide batter evenly among prepared pans. Bake for 28 to 32 minutes until a toothpick inserted in the center comes out clean.
07 - Allow cakes to cool in pans for 10 minutes, then transfer to wire racks to cool completely.
08 - Beat unsalted butter until smooth. Gradually add powdered sugar, then vanilla extract, mixing until creamy. Add heavy cream or milk as needed for the desired consistency.
09 - Tint most of the buttercream with teal gel food coloring, reserving some uncolored for crumb coating.
10 - Place rock sugar crystals into a bowl. Add a few drops of teal gel food coloring and gently mix until evenly coated. Let dry on parchment paper if necessary.
11 - Level cake layers as needed. Optionally, brush each layer with simple syrup for added moisture. Stack layers with a thin layer of buttercream between each.
12 - Cover assembled cake with a thin layer of uncolored buttercream. Chill for 20 minutes.
13 - Apply teal buttercream to the entire cake, smoothing the sides and top with an offset spatula.
14 - Using a serrated cake knife, carve a wedge or slice out of the cake side to expose the interior.
15 - Spread a thin layer of buttercream inside the cut-out area. Press colored sugar crystals into the buttercream, using lighter crystals in the center and darker ones at the edges.
16 - Paint edges with edible gold leaf or brush gold luster dust mixed with clear alcohol around the geode for a metallic finish.
17 - Adorn the cake with extra gold details and, if desired, a graduation-themed topper.
